import java.util.ArrayList;
import java.util.Collection;
@SuppressWarnings("all")
public class CollectionFor {
    public static void main(String[] args) {
        Collection col = new ArrayList();
        col.add(new book("张三", "大三", 15.5));
        col.add(new book("王五", "初一", 15.2));
        col.add(new book("张三", "小学", 15.9));

        for(Object book: col){  // 底层是迭代器
           // System.out.println("book" + book);
        }
         // I + Enter

        int [] nums = {777,2,3,4,5};
        for(int i : nums){  // i 代表的是下标代表的数
            System.out.println(i);
        }
    }
}
